Reversible steam engine



Dec. 16, 1924. 1,519,823

' L. N. DAVIS REvERsILE STEAM ENGINE Filed Jan. 24, 1922 2 sheets-mt 1 11mm "il" Leu/i6 N. am

nec. 16, 1924. 1,519,823

L. N. DAVIS REVERSIBLE STEAM ENGINE Filed Jan'. 24, 1922: 2 Sheets-Sheet2 Patented Dec. 16, 1924.

LEWS N. DAVS, OF AKRON, OHIO.

REVERSIBLE STEV ENG-INE.

Application filed. January 24, 1922.

To all lw71 om t may concern.'

Be it known that I, Lewis N. Davis, a citizen of the United States,`residing at Akron, in the county of Summit and State of Ohio, haveinvented certain new and useful Improvements in Reversible SteamEngines, of which the following is a specification.

The invention relates to steam engines in which the valve is controlledby an eccentric; andthe object of the improvement is to operate theengine valve for both directions of motion of the crank shaft with asingle eccentric, and without the use of a shifting link.

The object of the invention is attained by locating an eccentric ringaround the crank shaft at one side of a hub which may be a part of thefly wheel; by securing the ringl on a rock shaft journaled in the hubalongside of the crank shaft so that the center of the ring may be swungor shifted to one side or the other of the center of the crank shaft,und by providing means for turning the rock shaft and locking it invarious positions with reference to the crank shaft.

An embodiment of the invention is illustrated in the accompanyingdrawings, forming part hereof` in which- Figure 1 shows the improvementapplied to an upright, stationary engine;

Fig. 2, a side elevation of a portion of the engine;

Fig. 3, an elevation section of the same;

Fig. 4, an end view of the cam control means;

Fig. 5, a plan of the cam control sleeve;

Fig. 6, a plan of a modified form of the same; and

Fig. 7, a diagrammatic view illustrating the two extreme positions ofthe eccentric ring.

Similar numerals refer to similar parts throughout the drawings. i

An eccentric ring 8 surrounding a rotary shaft 9, which may he andpreferably is the crank shaft of the engine, is secured to a rock shaft10 journaled in the hub 11, which may be and preferably is part of thefly wheel 12 and is keyed upon the rotary shaft; so that the rock shaftis located along the side of and parallel with the rotary shaft.

The eccentric ring is preferably located at one end of the hub and iskeyed to one end Serial No. 531,394.

of the rock shaft which protrudes from the same end of the hub; and uponthe other end of the rock shaft which protrudes from the other end ofthe hub, is secured a rock u sleeve 1?)7^ upon the outer end of whichdiverging rock arms 1li extend astride the crank shaft.

A. shifting sleeve 15 is feathered upon the rotary shaft alongside therock sleeve, and is provided with cam wings 16 located and shaped inreverse position, the edges of which abut the inner sides of the rockarms at or near the ends thereof, for swinging the same one way or theother with reference to the center of the rotary shaft.

For smaller engines, a simple form of cam wings may he used, as shown inFig. 5, in which one rock arm rests on a flat seat 17 at the high end ofone wing while the other arm rests upon a flat seat 17 at the lower endof the other wing; from which seats the cam edges are inclined towardreversely positioned seats 18 and 18 at the other end of the wings; andit is evident that by sliding the shifting sleeve 16 endwise on therotary shaft, the rock arms 14- will he operated to turn the rock shaftin its journal in the huh of the tty wheel.

,fin end wise movement' of the shifting sleeve may he given hy a lever19 having a yoke 2O on its end engaging trunnions 21 on a ring swiveledon the end of the sleeve: which arms may he mounted on one end of a rockshaft 23 having an operating arm 24 on its other end in well knownmanner.

The parts are so arranged that when the rock shaft is turned by the camwings to the full extent in one direction, the eccentric ring will be inone operative position shown by full lines` in Fig. 7, with the cen--ter 25 at one side of the center f2.5 of the ro tary shaft: and when therock shaft turned by the cani wings to the full extent in the otherdirection, the eccentric ring will he swung to the other operativeposition, shown by broken lines in Fig. 7, with the center 2. at theother side of the center of the rotary shaft.

The dotted circle in Fig. 7 indicates the orbit of the center of theeccentric ring in its rotation around the center of the rotary shaft,and the dotted arc of a circle shows 'the portion of the orbit which thecenter of the eccentric travels when shifting from one llt) operativeposition to the other; the differential between said arc and the centerof the driving shaft representing one half of the valve travel.

For larger engines a compound form of cam flanges may be employed, asshown in Fig. 6, wherein each flange has differential seats at each endto control the shut olf in well known manner; thereby serving thc samepurpose as the second notch in the quadrant of the ordinary engine. Inthis compound form, the sleeve 15 is provided with the cam wings 16located and shaped in reverse position, the stepped flat seats 17a and17h being provided at the high end of one wing and the stepped seats 18aand 18b at the low end thereof. Similar stepped seats 18a and 18h" arelocated at the high end of the other wing and the stepped seats 17a' and17h at the low end thereof.

An eccentric strap 27 is journaled around the periphery of the eccentricring, and an eccentric rod 28 extends from the strap and is pivotallyconnected to the valve stem 29, operating endwise in the guide bracket30 for operating the engine valve in well known manner.

kI claim:

1. In an engine, a rotary shaft with a bearing secured on one sidethereof, a rock shaft journaled in the hearing alongside the rotaryshaft, an eccentric around the rotary shaft, rock arms on the rock shaftand means operating on the rock arms for turning the rock shaft to shiftthe eccentric into different positions.

2. In an engine, a valve, a rotary shaft with a bearing secured on oneside thereof, a rock shaft journaled in the bearing alongside the rotaryshaft, an eccentric round the rotary shaft secured to the rock shaft, aneccentric strap on the eccentric operatively connected with the valve,rock arms on the rockA shaft and means operating on the rock arms forturning the rock shaft to shift the eccentric into different positions.

3. In an engine, a valve, a rotary shaft with a hub secured thereon, arock shaft journaled in the hub alongside the rotary shaft, an eccentricaround the rotary shaft secured to the rock shaft, an eccentric strap onthe eccentric operatively connected with the valve, rock arms on therock shaft, and means operating on the rock arms for turning the rockshaft to shift the eccentric into different positions.

4. In an engine, a valve, a crank shaft with a hub secured thereon, arock shaft journaled in the hub alongside the crank shaft, an eccentricaround the crank shaft secured to therock shaft, an eccentric straponthe eccentric and operatively connected with the valve, rock arms on therock shaft and means operating on the rock arms for turning the rockshaft to shift the eccentric into different positions.

5. In an engine, a valve, a crank shaft with a fly wheel securedthereon, a rock shaft journaled in the fly wheel alongside thecrank-shaft, an eccentric around the crank shaft secured to the rockshaft, an eccentric strap around the eccentric operatively connectedwith the valve, rock arms onthe rock shaft and a shift sleeve featheredon the rotary shaft having cam wings operating on the rock shaft forturning the rock shaft to shift the eccentric into different positions.

6. In an engine, a rotary shaft with a bearing secured kon one sidethereof, a rock shaft journaled in the bearing alongside the rotaryshaft, an eccentric around the rotary shaft secured to the rock shaft,rock arms on the rock shaft astride the rotary shaft and a shiftingsleeve feathered on the rotary shaft,

having cam wings thereon operating on the rock arms for shifting theeccentric into different positions.

LEIIS N. DAVIS.

